The protooncogene c-jun is the cellular counterpart of the v-jun. oncogene of avian sarcoma virus 17. C-jun expression is activated in response to a diverse set of DNA-damaging agents including ara-C, UV radiation, topoisomerase II inhibitors, alkylating agents, and ionizing radiation. As an immediate early response gene that is rapidly induced by pleiotropic signals, c-jun may have important regulatory functions for cell cycle progression, proliferation, and survival. See Ryder, K., Lau, L. F., and Nathans, D. xe2x80x9cA gene activated by i:3 growth factors is related to the oncogene v-jun,xe2x80x9d Proc Natl Acad Sci USA. 85: 1487-1491, 1988; Schutte, J., Viallet, J., Nau, M., Segal, S., Fedorko, J., and Minna, J. xe2x80x9cjun-B inhibits and c-fos stimulates the transforming and trans-activating activities of c-jun, Cell. 59: 987-997, 1989; Neuberg, M., Adamkiewicz, J., Hunter, J. B., and Mueller, R. xe2x80x9cA fos protein containing the Jun leucine zipper forms a homodimer which binds to the AP-1 binding site,xe2x80x9d Nature. 341: 589-590, 1989; Mitchell, P. J. and Tjian, R. xe2x80x9cTranscriptional regulation in mammalian cells by sequence-specific DNA binding proteins,xe2x80x9d Science. 245: 371-378, 1989; Bohmann, D., Bos, T. J., Admon, T., Nishimura, R., Vogt, P. K., and Tijian, R. xe2x80x9cHuman protooncogene c-jun encodes a DNA binding protein with structural and functional properties of transcription factor AP-1,xe2x80x9d Science. 238: 1386-1392, 1988; Kharbanda, S. M., Sherman, M. L., and Kufe, D. W. xe2x80x9cTranscriptional regulation of c-jun gene expression by arabinofuranosylcytosine in human myeloid leukemia cells,xe2x80x9d J Clin Invest. 86: 1517-1523, 1990; Rosette, C. and Karin, M. xe2x80x9cUltraviolet light and osmotic stress: activation of the JNK cascade through multiple growth factor and cytokine receptors,xe2x80x9d i Science. 274: 1194-7, 1996; Rubin, E., Kharbanda, S., Gunji, H., and Kufe, D. xe2x80x9cActivation of the c-jun protooncogene in human myleloid leukemia cells treated with etoposide,xe2x80x9d Molecular Pharmacology. 39: 697-701, 1991; Dosch, J. and Kaina, B. xe2x80x9cInduction of c-fos, c-jun, junB and junD mRNA and AP-1 by alkylating mutagens in cells deficient and proficient for the DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT) and its relationship to cell death, mutation induction and chromosomal instability,xe2x80x9d Oncogene. 13: 1927-35, 1996; Chae, H. P., Jarvis, L. J., and Uckun, F. M. xe2x80x9cRole of tyrosine phosphorylation in radiation-induced activation of c-jun protooncogene in human lymphohematopoietic precursor cells,xe2x80x9d Cancer Res. 53: 447-51, 1993; and Karin, M., Liu, Z.-G., and Zandi, E. xe2x80x9cAP-1 function and regulation,xe2x80x9d Current Opinion in Cell Biology. 9: 240-246, 1997.
C-jun encodes the nuclear DNA-binding protein, JUN, that contains a leucine-zipper region involved in homo- and heterodimerization. JUN protein dimerizes with another JUN protein or the product of c-fos gene and forms the activating protein-1 (AP-1) transcription factor. JUN-JUN homodimers and JUN-FOS heterodimers preferentially bind to a specific heptameric consensus sequence found in the promoter region of multiple growth regulatory genes. Alterations of c-jun protooncogene expression can therefore modulate the transcription of several growth-regulators affecting cell proliferation and differentiation. See Ryder, K., Lau, L. F., and Nathans, D. xe2x80x9cA gene activated by growth factors is related to the oncogene v-jun,xe2x80x9d Proc Natl Acad Sci USA. 85: 1487-1491, 1988; Neuberg, M., Adamkicwicz, J. Hunter, J. B., and Mueller, R. xe2x80x9cA fos protein containing the Jun leucine zipper forms a homodimer which binds to the AP-1 binding site,xe2x80x9d Nature. 341: 589-590, 1989; Karin, M., Liu, Z.-G., and Zandi, E. xe2x80x9cAP-1 function and regulation,xe2x80x9d Current Opinion in Cell Biology. 9: 240-246, 1997; Angel, P., Allegretto, E. A., Okino, S. T., Hattori, K., Boyle, W. J., Hunter, T., and Karin, M. xe2x80x9cOncogene jun encodes a sequence-specific trans-activator similar to AP-1,xe2x80x9d Nature. 332: 166-170, 1988; and Musti, A. M., Treier, M., and Bohmann, D. xe2x80x9cReduced ubiquitin-dependent degradation of c-Jun after phosphorylation by MAP kinases,xe2x80x9d Science. 275: 400-402, 1997.
C-jun plays a pivotal role in Ras-induced transformation and has also been implicated as a regulator of apoptosis when de novo protein synthesis is required. C-jun induction is required for ceramide-induced apoptosis and stress-induced apoptosis after UV exposure or other forms of DNA damage. This induction is thought to be triggered by activation of JUN-N-terminal kinases (JNKs) (also known as stress-activated protein kinases) which leads to enhanced c-jun transcription by phosphorylation of JUN at sites that increases its ability to activate transcription. Ectopic expression of a dominant-negative c-jun mutant lacking the N terminus or a dominant-negative JNK kinase abolishes stress-induced apoptosis. See Karin, M., Liu, Z.-G., and Zandi, E. xe2x80x9cAP-1 function and regulation,xe2x80x9d Current Opinion in Cell Biology. 9: 240-246, 1997; Collotta, F., Polentarutti, N., and Mantovani, A. xe2x80x9cExpression and involvement of c-fos and c-jun protooncogenes in programmed cell death induced by growth factor deprivation in lymphoid cell lines,xe2x80x9d J. Biol. Chem. 267: 18278-18283, 1992; Ham, J., Babij, C., Whitfield, J., Pfarr, C. M., Lallemand, D., Yaniv, M., and Rubin, L. L. xe2x80x9cA c-Jun dominant negative mutant protects sympathetic neurons against programmed cell death,xe2x80x9d Neuron. 14: 927-939, 1995; Verheij, M., Bose, R., Lin, X. H., Yao, B., Jarvis, W. D., Grant, S., Birrer, K M. J., Szabo, E., Zon, L. I., Kyriakis, J. M., Haimovitz F A., Fuks, Z., and Kolesnick, R. N. xe2x80x9cRequirement for ceramide-initiated SAPK/JNK signalling in stress-induced apoptosis,xe2x80x9d Nature. 380: 75-9, 1996; Hibi, M., Lin, A., Smeal, T., Minden, A., and Karin, M. xe2x80x9cIdentification of an oncoprotein- and UV-responsive protein kinase that binds and potentiates the c-Jun activation domain,xe2x80x9d Genes Dev. 7: 2135-48, 1993; Derijard, B., Hibi, M., Wu, I. H., Barrett, T., Su, B., Deng, T., Karin, M., and Davis, R. J. xe2x80x9cJNK1: a protein kinase stimulated by UV light and Ha-Ras that binds and phosphorylates the c-Jun activation domain,xe2x80x9d Cell. 76: 1025-37, 1994; and Chen, Y. R., Wang, X., Templeton, D., Davis, R. J., and Tan, T. H. xe2x80x9cThe role of c-Jun N-terminal kinase (JNK) in apoptosis induced by ultraviolet C and gamma radiation. Duration of JNK activation may determine cell death and proliferation,xe2x80x9d J Biol Chem. 271: 31929-36, 1996.
Protein tyrosine kinases (PTK) play important roles in the initiation and maintenance of biochemical signal transduction cascades that affect proliferation and survival of B-lineage lymphoid cells. Oxidative stress has been shown to activate BTK, SYK, and Src family PTK. It is known that PTK activation precedes and mandates radiation-induced activation of c-jun protooncogene expression in human B-lineage lymphoid cells (Chae, H. P., Jarvis, L. J., and Uckun, F. M. Cancer Res. 53: 447-51, 1993). However, the identity of the PTK responsible for radiation-induced c-jun activation is not yet known. See Uckun, F. M., Waddick, K. G., Mahajan, S., Jun, X., Takata, M., Bolen, J., and Kurosaki, T. xe2x80x9cBTK as a mediator of radiation-induced apoptosis in DT-40 lymphorna B cells,xe2x80x9d Science. 273: 1096-100, 1996; Kurosaki, T. xe2x80x9cMolecular mechanisms in B cell antigen receptor signaling,xe2x80x9d Curr Opin Immunol. 9: 309-18, 1997; Uckun F. M., Evans W. E., Forsyth C. J., Waddick K. G., T-Ahlgren L., Chelstrom L. M., Burkhardt A., Bolen J., Myers D. E. xe2x80x9cBiotherapy of B-cell precursor leukemia by targeting genistein to CD19-associated tyrosine kinases.xe2x80x9d Science 267:886-891, 1995; Myers D. E., Jun X., Waddick K. G., Forsyth C., Chelstrom L. M., Gunther R. L., Turner N. E., Bolen J., Uckun F. M. xe2x80x9cMembrane-associated CD19-LYN complex is an endogenous p53-independent and bcl-2-independent regulator of apoptosis in human B-lineage lymphoma cells.xe2x80x9d Proc Nat""l Acad Sci USA 92: 9575-9579, 1995; Tuel Ahlgren, L., Jun, X., Waddick, K. G., Jin, J., Bolen, J., and Uckun, F. M. xe2x80x9cRole of tyrosine phosphorylation in radiation-induced cell cycle-arrest of leukemic B-cell precursors at the G2-M transition checkpoint,xe2x80x9d Leuk Lymphoma. 20: 417-26, 1996; Qin, S., Minami, Y., Hibi, M., Kurosaki, T., and Yamamura, H. xe2x80x9cSyk-dependent and -independent signaling cascades in B cells elicited by osmotic and oxidative stress,xe2x80x9d J Biol Chem. 272: 2098-103,1997; Saouaf, S. J., Mahajan, S., Rowley, R. B., Kut, S., Fargnoli, J., Burkhardt, A. L., Tsukada, S., Witte, O. N., and Bolen, J. B. xe2x80x9cTemporal differences in the activation of three classes of non-transmembrane protein tyrosine kinases following B cell antigen receptor surface engagement,xe2x80x9d Proc Natl Acad Sci USA. 91: 9524-28, 1994; Law, D. A., Chan, V. F. W., Datta, S. K., and DeFranco, A. L. xe2x80x9cB-cell antigen receptor motifs have redundant signalling capabilities and bind the tyrosine kinases PTK72,Lyn and Fyn,xe2x80x9d Curr Biol. 3: 645-57, 1993; Hibbs, M. L., Tarlinton, D. M., Armes, J., Grail, D., Hodgson, G., Maglitto, R., Stacker, S. A., and Dunn, A. R. xe2x80x9cMultiple defects in the immune system of Lyn-deficient mice, culminating in autoimmune disease,xe2x80x9d Cell. 83: 301-311, 1995; Aoki, Y., Isselbacker, K. J., and Pilai, S. xe2x80x9cBruton tyrosine kinase is tyrosine phosphorylated and activated in pre-B lymphocytes and receptor-ligated B cells,xe2x80x9d Proc Natl Acad Sci USA. 91: 10606-10609, 1994; Jugloff, L. S. and Jongstra Bilen, J. xe2x80x9cCross-linking of the IgM receptor induces rapid translocation of IgM-associated Ig alpha, Lyn, and Syk tyrosine kinases to the membrane skeleton, J Immunol. 159: 1096-106, 1997; Thomis, D. S., Gumiak, C. B., Tivol, E., Sharpe, A. H., and Berg, L. J. xe2x80x9cDefects in B lymphocyte maturation and T lymphocyte activation in mice lacking Jak 3,xe2x80x9d Science. 270: 794-797, 1995; Nosaka, T., Van Deursen, J. M., Tripp, R. A., Thierfelder, W. E., Witthuhn, B. A., McMickle, A. P., Doherty, P. c., Grosveld, G. C., and Ihle, J. N. xe2x80x9cDefective lymphoid development in mice lacking Jak 3,xe2x80x9d Science. 270: 800-802, 1995.
U.S. patent application Ser. No. 09/087,479 (entitled Quinazolines For Treating Brain Tumor; filed 28 May 1998) discloses hydroxyquinazoline derivatives that exhibit potent cytotoxicity against human glioblastoma cells (i.e. brain tumor cells). Because JAK-3 is not known to be present in these glioblastoma cells, the cytotoxic activity of the hydroxyquinazoline derivatives is not believed to result from inhibition of JAK-3 activity. Additionally, the cytotoxic activity of the hydroxyquinazoline derivatives is not known to result from the inhibition of c-jun activation.
There is currently a need for therapeutic agents and methods that are useful for preventing or reducing cell damage that results from exposure to radiation and chemical agents that cause DNA-damage. There is also a need for chemical agents as well as in vitro and in vivo methods that can be used to further investigate the biological pathways associated with DNA-damage that results from exposure to radiation or chemical agents.
The invention provides a method comprising inhibiting c-jun expression in cells (e.g. mammalian or avian) by contacting the cells (in vitro or in vivo) with a substance that inhibits the activity of Janus family kinase 3 (JAK-3).
The invention also provides a therapeutic method for preventing or treating a pathological condition in a mammal (e.g. a human) wherein c-jun activation is implicated and inhibition of its expression is desired comprising administering to a mammal in need of such therapy, an effective amount of a substance that inhibits the activity of JAK-3.
The invention also provides novel compounds of formula I as well as processes and intermediates useful for their preparation.
The invention also provides substances that are effective to inhibit JAK-3 for use in medical therapy (preferably for use in treating conditions that result from exposure to radiation or to chemical agents that cause DNA damage), as well as the use of substances that inhibit JAK-3 for the manufacture of a medicament for the treatment of a condition that is associated with exposure to radiation, or to chemical agents that cause DNA damage.